1. Field of the Invention
This invention relates to a built-in antenna, an electronic device using the built-in antenna, a method of making the built-in antenna and a method of installing the built-in antenna.
2. Description of the Related Art
Built-in antennas are conventionally used in a mobile terminal device such as a cellular phone and a personal computer. The built-in antenna is fixed to a printed-circuit board, a cellular phone body cover etc. of the device. In general, the fixation is made such that a copper antenna plate (conductor plate) with a given shape and a positioning penetrating hole formed by punching is attached to the printed-circuit board or plastic molded body while fitting a positioning protrusion formed on the printed-circuit board or plastic molded body to the positioning penetrating hole, then fixing the antenna plate thereto by using adhesive tape or the like (first method, disclosed in, e.g., Japanese patent application laid-open No.10-163748 (page 2 and FIG. 2)), or by heating and melting the positioning protrusion (second method, disclosed in, e.g., Japanese patent application laid-open No.10-190512). Meanwhile, the antenna plate is electrically connected to the conductive pattern of printed-circuit board through a metallic contact pin.
However, in the first method, the step of attaching the adhesive tape to the antenna plate is additionally required and therefore it is not suitable for mass production. Further, after attaching the antenna plate to a molded body, the position of antenna plate cannot be changed to fit the shape of molded body. The adhesive tape itself is not suitable because it may affect the antenna characteristics.
In the second method, a special tool for heating and melting the protrusion requires a lot of skill to master. Further, after attaching the antenna plate to a molded body, the position of antenna plate cannot be changed to fit the shape of molded body.